United States Law

The law of the United States consists of many levels of codified and unmodified forms of law, of which the most important is the United States Constitution, the foundation of the federal government of the United States. The Constitution sets out the boundaries of federal law, which consists of constitutional acts of Congress, constitutional treaties ratified by Congress, constitutional regulations promulgated by the executive branch, and case law originating from the federal judiciary.

The Constitution and federal law are the supreme law of the land, thus preempting conflicting state and territorial laws in the fifty U.S. states and in the territories. However, the scope of federal preemption is limited, because the scope of federal power is itself rather limited. In the unique dual-sovereign system of American federalism , states are the plenary sovereigns, while the federal sovereign possesses only the limited supreme authority enumerated in the Constitution. Indeed, states may grant their citizens broader rights than the federal Constitution as long as they do not infringe on any federal constitutional rights Thus, most U.S. law  consists primarily of state law, which can and does vary greatly from one state to the next.

Types Of laws are

Procedural law
        Criminal procedure
        Civil procedure 
Substantive law
        Criminal law
        Contract law
        Tort law